In the interests of fuel economy, there is an increasing drive within the automotive industry towards weight reduction of the component parts of vehicles. A vehicle wheel bearing is one example of an automotive component where weight reduction is desirable, also in view of the fact that the wheel bearings belong to the unsprung weight of a vehicle. Raceways of the bearings need to be made from a material of sufficient hardness in order to withstand the stresses of rolling contact. Titanium and certain ceramics are materials that possess the necessary mechanical properties and are also low in weight. They are also expensive and, consequently, bearing steel is more commonly used. Bearing steel has excellent hardenability but cannot be viewed as a lightweight material. Thus, one solution for reducing the weight of a wheel bearing comprising bearing steel is to form the bearing rings from bearing steel and to form further structural elements of the wheel bearing from a fiber-reinforced polymer.
An example of such a wheel bearing is disclosed in JP2011178314. The wheel bearing has a flanged inner ring, for connecting a vehicle wheel and brake disc to the bearing, and has a flanged outer ring for connecting the bearing to e.g. a steering knuckle. Each bearing flange is made of a laminated body of a carbon-fiber prepreg, formed by e.g. braiding the fibers and binding them in resin around a cylindrical surface of the bearing inner ring or outer ring.
There is still room for improvement.